Callen B W, Lowenberg B F, Lugowski S, Sodhi R N, Davies J E
Centre for Biomaterials, University of Toronto, Ontario, Canada.
J Biomed Mater Res. 1995 Mar;29(3):279-90. doi: 10.1002/jbm.820290302.
Passivation of Ti6Al4V and cpTi implants using methods based on the ASTM-F86 nitric acid protocol are used with the intention of reducing their surface reactivity, and consequently the corrosion potential, in the highly corrosive biologic milieu. The ASTM-F86 passivation protocol was originally developed for surgical implants made of stainless steel and chrome cobalt alloy. Using X-ray photoelectron spectroscopy (XPS) to examine the effect of nitric acid passivation on the surface oxide layer of mill-annealed Ti6Al4V and cpTi, we have found that such treatment actually reduced the oxide thickness on the alloy while having no significant effect on the pure metal. These results correlated with observations obtained using graphite furnace atomic absorption spectrophotometry (GFAAS) to detect trace element release from solid, mill-annealed, Ti6Al4V and cpTi into serum-containing culture medium. We detected significantly greater levels of Ti, Al, and V in the presence of passivated compared to nonpassivated Ti6Al4V. In contrast, nitric acid passivation did not influence Ti release from mill-annealed cpTi. These results, derived from two mill-annealed Ti-based metals, would indicate that re-examination of ASTM-F86-based passivation protocols with respect to Ti6Al4V should be considered in view of the widespread use of this alloy for biomedical devices.
使用基于ASTM-F86硝酸规程的方法对Ti6Al4V和纯钛植入物进行钝化处理，目的是在高腐蚀性生物环境中降低其表面反应性，进而降低腐蚀电位。ASTM-F86钝化规程最初是为不锈钢和铬钴合金制成的外科植入物开发的。通过X射线光电子能谱（XPS）研究硝酸钝化对轧制退火态Ti6Al4V和纯钛表面氧化层的影响，我们发现这种处理实际上减小了合金上的氧化层厚度，而对纯金属没有显著影响。这些结果与使用石墨炉原子吸收光谱法（GFAAS）检测轧制退火态Ti6Al4V和纯钛固体中微量元素向含血清培养基中释放的观察结果相关。我们检测到，与未钝化的Ti6Al4V相比，钝化后的Ti6Al4V中钛、铝和钒的含量显著更高。相比之下，硝酸钝化对轧制退火态纯钛的钛释放没有影响。这些来自两种轧制退火态钛基金属的结果表明，鉴于Ti6Al4V在生物医学设备中的广泛应用，应考虑重新审视基于ASTM-F86的Ti6Al4V钝化规程。
